That’s essentially the right recipe, and it sure as heck is cheaper long term than buying Terro (which is a good product in terms of effectiveness, but it must be making the maker a fortune!) However, the cotton balls are messy and leave bait behind to clean up. We clean out & refill Terro “traps” or use our own — which can be almost anything that will hold a little of the bait, stay in place, and ants can easily get into. I often position a partially flattened soda can outside out kitchen wall such that it is in shade, rain doesn’t get in, but the ants can. Rocks, etc., can help keep the can in place, and this will hold a couple oz. of bait: Months’ worth.
Soon as the snow melts away, I’ll start watching for the annual migration. Right now, snow is still too deep to worry about ants for a while.